According to disposition locations of light sources in a backlight module, the backlight modules may be classified into two types, edge-lit type and direct-lit type. In the direct-lit type backlight module, light sources are disposed directly below a liquid crystal display panel, so that the liquid crystal display panel can achieve high light intensity, so liquid crystal display products of this type are mostly used in displays with high brightness requirements, such as computer displays, liquid crystal televisions, etc.
In large-size liquid crystal display products, as shown in FIG. 1, in order to avoid causing a dislocation between light sources 50 and a reflective sheet 20 in a backlight module because of the shock during a process of carrying display devices, positioning posts 30 in existing direct-lit type backlight modules are disposed on a back plate 10, a reflective sheet 20 located on the back plate 10 is provided with a plurality of opening areas 200 at locations corresponding to the positioning posts 30, and top ends of the positioning posts 30 penetrate through the opening areas 200 for securing the reflective sheet 20.
However, the positioning posts 30 are usually made of a transparent material, and the transparent positioning posts are located between the reflective sheet 20 and the light sources 50, which will influence the reflection effect of light rays, so that viewers may see remnant profile shadow of the positioning posts 30 on the display screen, which leads to poor display quality.